Thread-controlling mechanism for sewing machines



P. A. HE RR.

THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

APPLICATION FILED JUNE II. I918. 1 102,930. N Patented Jan. 10, 1922.

4 SHEETS-SHEET I.

P. A. HERB. THREAD CONTROLLING MECHANISM FOR SEWING MACHlNES.

, APPLICATION FILED JUNE 11, l9l8. 1,402,930

Patented Jan. 10,1922.

4 SHEETS-SHEET 2.

INVE TOR V m. r,

ITTORNEY P. A. HERR. THREAD CONTROLLING MECHANISM FOR SEWING MACHINES.

- APPLICATION FILED JUNE H, 1918.

1 ,402,930 Patented Jan. 10,1922.v

4 SHEETS-SHEET a.

WITNESSES INVENTOR I BY MK%/ 4 P. A. HERR. THREAD CONTROLLING MECHANISMFOR SEWING MACHINES.

APPLICATION FILED JUNE II, 1918- Patented Jan. 10, 1922, v

4 SHEETS-SHEET 4.

,E snauomu LOOP SEIZING TAKE UP VEEDLE EYE TOP OF THRORT PLRTE STITCH 0m S E S S E N W W AT ORNEY' PARK A. man. or rrrnnsrnn, .nnwenias-Eessienon'ro rnn snvenn mannere Tennis company, a coeroaarron or newanasnr.

THREAD-CONTRDLLZNG MECHANI$M MACHINES.

Patented Jan; 10, 1922.

Application filed June 11, 1918. -semen no. 239,369.

To all t/rizmn it may concern Be it known that I, PARK A. Hnnn, acitizen of the United States, residing at Hillside, in the county ofUnion and State of New Jersey, have invented certain new and usefulImprovements in; T hread-Controlling liflechanisms for Sewin Machines.of which the following is a specification, reference being had thereinto the accompanying drawings.

This lnvention relates to sewing machines and particularly to mechanismused in conjunction therewith for controlling the thread as it passes tothestitch-forming mechanism for assisting the same in perfecting thestitch.

In th evolution of a modern take-up or sewing machines it has been foundthat any required thread-control may be obtained by the use of aproperly designed cam (usually of a barrel or face type) to actuate athreadengaging member, but such take-ups are detective in oneparticular, to wit, they limit the speed of operation of the machine.Further development evolved the link actuated take-up which is inextensive use to-day because it is capable of operation at a high speedbut it is defective because it lacks the nicety of thread control whichis desirable and which has been obtained with the camactuated take-up.

The present invention aims to improve the construction and operation or"the link-actuated type of take-up by a combination and arrangement oflinks and levers which permit operation of the machine at a high speedand which also possesses the nice thread control that is the desideratumat the present day.

Essentially the invention comprises a takeup arm pivoted on the head ofth machine with its apertured thread-engaging end vibratingly arrangedat the front of the machine head. The arm is oscillated through a linkfrom a. lever which is fulcrumed eccentrically on a rotary disk withinthe head of the machine and while the lever is being bodily rotated itis swung about its fulcrum sons to carry a pin connecting the'link andlever to and from the axis of the diskto vary its action, such swingingmotion beingeffected by articulating the other end of the lever to astrap which embraces a stationary f disk disposed'eccentrically of theaxis of the rotary disk. The pin connection between the link andlevermoves in an ape the several proximately heart-shaped path theresultant of two combined circularly movable .elements and throughthe'pin connection the end of the take-up arm is vibrated in'a fashion-.controll'ing the thread. nicely throughout each stitch-forming cycleof operations. The mechanism is simple, du-

rable capable ofop'eration at a'high speed, once adjusted is not likelyto vary inits cooperative action with the stitch-forming mechanismduring the lifeoi" the machine and constitutes a marked advance in theart.

The invention is illustrated in the accompanying drawings, in whichFig.1 represents the linkflactuated take-up applied to a lock-stitchmachine, the parts being shown in end elevation in th relativepositionthey occupy when the needle-eye is at the level of thethroat-plate. Fig. 2 the same just after the loop-taker has entered theneedleloop. Fig. 3 thesame at the commencement of cast-oil. Fig. etthesame when the stitch is completely set. Fig 5 shows th construd tion infront elevation Fig. 6 is a section on the line A-B, Fig. '5. Fig. 7 isa sectional detail of the actuating crank-pin.

Fig 8 is a diagram representing the relative movementof the take-up andneedle-eyes.

Fig. 9 is a motion diagram representing graphically the various postions assumed by the take-up during a stitch-forming cycle of operation.

In the c'lrawings the invention is illustrated. applied to a machine ofa lock-stitch type having a needle 1 on a needle-bar'Q reciprocatedthrough a link 4 from a crankpin 5 radially spacedfrom the axis of a'disk 6 which is fast on. a driving shaft 7 mounted in bearings in theoverhanging arm 8 and terminating in the head 9. A pressertoot 10 iscarried by a bar 11 and cooperates with a feed-dog (not shown) toadvance the work a stitch length at a time in a manner well known.

, Below the plane of the work-support and throat-plate'is a loop-takeror hook l2 and bobbin 13 which in the machine illustrated are of theoscillatory type and cooperate with the needle in a well understoodfashion but a rotary type may be used if desired. Any suitable mechanismmay be used to impart the requisitemotion to the loop-taker or hook 12to insure cooperation thereof with the needle. k I r x I,

A thread-engaging element 15, constitutjoints of the linkage actuatingling mechanism,,is fulcrumed on a pin 16 in the rear of the head of thmachine'with its .body free to vibrate in a plane slightly to one sideof and parallel with th needle-bar and with its free apertured endl7extending to the front of the machine. An arm 18' firmly secured on theother end of the pin 16 is connected by a link 19 to an arm 20 fast ononeend of the crank-pin 5 to whose opposite end is likewise fast-asecond arm 21. A pin19' loosely connects the link 19 and arm 20. The arm21' is loosely joined by a pin 22 to a strap 23 which embraces astationary disk or eccentric 2a integral or otherwisefixed to a sleeve25 encircling the driving shaft 7 and secured-for angular adjustmentthereabout by the clamp-screw 26 which is threaded into the overhangingarm of the machine. If desired the stationary disk 24 may be madeadjustable to vary its throwi. e., the distance between the centers CCand CD.' Fig. 9,'by any suitable mechanical expedient of which there area great variety known to those skilled in the art.

Upon the front side of the head and overhanging arm ofthemachinethreaded-'guiding devices are mounted. These devices comprise constanttensions 27-28, an automatic thread-check 29 (which may be omit ted ifdesired), a thread-guiding roller 30 and a fixed thread-eye 31. Thethread passes from the'supply through the tensions 2728 and automaticthread-check 29 and throadguiding roller 30 to the'apertured end 17 ofthe thread-engaging member ofthe take-up and thence through the fixedeye 31 to the eye of the needle. 7

In the operation of themachine the needle passes through the work N andshortly after it starts to ascend throws out a loop of thread that isentered by the loop-taker 12 which carries the needle-loop to aposition, uch as shown in Fig. 8, where the loop of thread is shed orcast off, encircling the bobbin-thread to form the lock-stitch as is Iwell understood.

In Fig. 8 the curves of the needle and take-up together with the motiondiagram in Fig 9 portray the action of the linkage operating the take-upbetter than words can describe. From a consideration of these figures itwill be seen that the take-up acts'to set the stitch after the needlehas been started down at that stage in the cycle of st tch-formingoperations indicatedby the arrow C, Fig. 8;

first at an accelerated rate and then in a retarded rate, its movementbeing slowest about the time the needle-loopis entered by the loop'taker which occurs just before the I parts reach the positionshown inFig. 2 and i at that stage'in the cycle of operations in- While theneedle descends to and through the work thread is given up thereofrequired to pass around the bobbin.

When the loop-taker arrives at cast-off or shedding position, at thatstage in the cycle of operations indicated by the arrow E, Fig. 8, thethread is in the condition illustrated in Fig. 3, there being no moreexcess slack at this time than is prudent to allow as a factor ofsafety. After cast-off the parts move from the position shown'in Fig. 3to that shown in Fig. 4;, the thread-engaging member 15 rising from itslowest to its highest position and setting the stitch. Most of thequantity of thread required to pass around the bobbin is taken up in acircular movement of the driving shaft 7 through an angle of about 45,the small quantity of thread remaining being taken up and the stitch'seteasily and gradually during the succeeding 45 turn of the driving shaft.Thus the critical stage in handling the thread is performed with anicety, force piercing or breaking of the thread in this way is thusprovided against. It is also noted that there is an approach to a dwellin the down stroke of the take-up at the time the loop-taker enters theneedle-loop and that the function of this dwell approximation orretardation is to 'prevent'an excess amount of slack thread between thework and the thread engaging member 15 in order to preventthe threadfrom becoming tangled about the end of the member or other projectingportions of the machine in proximity with the take-up. In short thethread is controlled substantially in the manner that it has beencontrolled heretofore with. cam actuated take-ups by a linkage whichdoes not, however, limit the speed at which the machine may be operated.

For the convenience of those skilled in the art it is to be noted thatthedimensions shown in Fig. 9 of the original drawing crank 20 521. Thedifferent positions of the linkage points are indicated by the numeralsfrom 1 to 8, exponents being ap pended to the several series of numbersto distinguish the several joints ofthe linkage from one another.

The distinguishing feature of the presen invention as it iscoinprehended at this time resides in the idea of shifting theconnection 19 between the arm 20 and the link 19 while it is rotating,said conection. constituting what. may be loosely termed a shiftablecrank-pin which has acombined' rotary and transverse movement withrespect to an imaginary axis coincident with the axis of the drivingshaft 7.

The path of the connection 19 between the link 19 and arm 20 is nearlyheart'shape and is the resultant of rotating the fulcrum of thebellcranlolever 20- 5- 21 about the axis of the shaft 7 with an end ofone arm of the bellcrank lever confinedto move in a circular patheccentric to the path of the crankpin "5. In other words the actuatedend of the link 19 is moved in a path the resultant of two circularlymoving elements in eccen' trio relation.

In the drawings and in the foregoing description the construction hasbeen described specifically with a view to enabling those skilled in theart constructing and compounding the same, but it is to be distinctlyunderstood that the principle of the invention is not confined to thespecific proportion and arrangement; of the parts. Obviously it may beused to handle looperthreads as well as needle-threads, its positionupon the head of the machine (when used there) may be varied, therelative proportions of the several membersof the linkage may be variedto alter the action of the thread-engaging member upon the'thread. Thelever 16-18 and the bellcrank 20--521 may be of the first, second orthird order if desired. The dri ing shaft 7 in the machine illustratedrotates but the invention might be applied to a machine whosecorresponding shaft is oscillated or rocked. These and many otherchanges might be effected without departing from the principle of theinvention which is capable of extensive modification because of thechanges in the action of the linkage which result, as I have discovered,from varying the angular relation of the disks 6 and 24: relative to theaxis of the shaft 7 and the spacing of their centers and from varyingthe relative lengths of the arms and link, and also from varying therelation and distance between the axes of pin 16 and shaft 7 1 Havingthus set forth the nature of the invention, what I claim herein 'is:

1. In a sewing machine, in combination with stitch-forming mechanism,thread con trolling mechanism including a thread-engaging member, meansfor moving the thread-engag ng member to govern the thread as demandedbythe stitch-forming mechanism in perfecting the stitch including a linkconnected tothe thread-engaging m mbe and eaus.;. fo i parti g oc ailinka movement whereby a point on said link spaced from said connectionwill have a combined rotary and transverse movement with respect to animaginary axis during each stitch-forming cycle of operat1ons,sa1d

latter means comprising a crank mounted on a, pivot movable in a curvedpath, and means for turning the crank on the pivot as it traverses saidpath.

2. In a sewing machine, in combination,

stitch-forming mechanism and thread controlling mechanism including a.thread-engaging member, a link operatively connected through one of itsends to the threadeng'aging member, a rotary shaft, a lever fulcrumedeccentrically of said shaft and movable both with and independently ofsaid shaft and having one of its ends connected to said link, and meansfor operating the lever to obtain an angular rotation of the lever aboutits own fulcrum while said shaft rotates the fulcrum of the leverwhereby the threadeengaging member connected to the other end thereofmay be made to control the thread passing to the stitch-formingmechanism, to perfect the formation of each stitch.

3. In a sewing machine, in combination, stitch-forming mechanism, andthread-controlling mechanism including a thread-engaging member, a linkconnected at one end to the thread-engaging member, a member operativelyconnected to the other end of the link, said member being movable aboutan imaginary axis, and means for moving said member about said imaginaryaxis and simultaneously varying its eccentricity rela tive to the axisin order to accelerate and retard the action of thethread-engagingmember to su1t the requirements of the stitch beingformed.

4. In a sewing machine, in combination, a needle, a shaft connected toand operating the needle, an implement cooperating with the needle toform, stitches, thread controlling mechanism including a thread-engagingmember, a link at one end pivotally connected to said member, anactuating member connected to the other end of said link, and means formoving said actuating member to and from the axis of said shaft andsimultaneously carrying it around with said shaft during astitch-forming cycle of operations whereby the action of the threadcontrolling mechanism may be varied as demanded by the cooperatingneedle and implement to perfect the. formation of-successive stitches.

5. In a sewing machine, in combination,

a needle, a needle-bar, a needle-bar operating shaft, 21: take-upmember, a lever fulcrume'd eccentrically of and carried by said shaft,means connecting the lever and takeup, and means for opera ing theleverto cause its point of connection with the take up to rapidly approach,pause and rapidly recede from the axis of the needle-bar actu atingshaft whereby the take-up member may be made to control the thread asrequired.

6.'In a sewing machine, in combination, stitch-forming mechanism andthread-controlling mechanism includinga th.read-engaging member having afixed fulcrum, and means for operating the thread-engaging memberincluding 'a shiftable member, a lever carrying said shiitable member,circularly movable elements eocentrically disposed relatively to oneanother and one oi which drives the other, said lever having a portionconstituting a link between said cir cularly movable elements anddetermining the path and rate of movementof said shiftable member, and aconnection between said shiftable member and said thread-engagingmember.

7. In'a'sewing machine, in combination,

stitch-forming mechanism including a nee- 'dle and a shaft for operatingthe same, and thread-controlling mechanism including a thread-engagingmember fulcrumed on a relatively stationary support, an actuating means,a link connecting said actuating means and said thread-engaging member,means for moving said actuating means in a curved path enclosing theaxis of the operating shaft whereby the thread-engaging Vmember may bemoved to control the thread throughout a stitch-forming cycle ofoperations.

8. In a sewingmachine having stitchforming mechanism including a needle,loop-taker and a-shaft for operating the same in combination withthread-coritroL ling mechanism including a thread-engaging member and alinkage formoving the same to give up thread in a gradually decreasingquantity during the descent of the needle and before the loop-takerenters the needleloop, thereafter to increasingly rapidly give up threaduntil the loop-taker arrives at cast-off position, then to rapidly takeup most of the thread before the needle reaches the upper limit of itsstroke, and finally to set the stitch afterthe needle starts down with agradually retarded movement.

9. In a sewing machine having stitchforming mechanism, in combinationwith thread-controlling mechanism including a thread-engaging memberfulcrumed on a stationary part of the machine, a link connected 'at' oneend to said member, a lever which is fulcrumed on a circularly movableelement and which is connected at one end to said link, and means forshifting the point of connection between the lever and link during eachstitch-forming cycle of operations.

10. In a sewing machine havingstitch-form- I neoaeeo ing mechanism, incombination with thread" controlling mechanism including athreadengagingmember, 'a link connected at one end to said member, a lever fulcrumedon an arcuately movable element and connectedto the other end of saidlink, and .an eccentric element for governing the movement of said.lever about its fulcrum during arcuate movement oi the fulcrum of thelever with the movable element upon which it is sup ported. V i

11. In a sewing machine having a needle and loop-taker, in combination,thread-controlling mechanism including a thread-engaging member and linkmechanism for operating said member to cause it to decrease its givingup movement when the needle starts to rise and throw out a loop forentrance by the loop-taker, then tocause it to give up thread to theloop-taker until the needle-loop is about to be shed, and finally tocause .it to rapidly take up thread immediatelyafter the loop-takerreaches shedding position. I

12. In a lock-stitch sewing machine having a needle, loop-taker andbobbin, a shaft, a thread-controlling mechanism including a circularlymovable element operated by said 7 shaft, a lever fulcrumed on andmovable with said circularly movable element, a takeup member linked toonearm of said lever, and means for moving the other arm of said levertoward and from said shaft during circular movement of the fulcrum ofthe lever with said circularly movable element, whereby theneedle-thread be controlled by the thread-engaging member to meet/therequirements of the stitch-forming mechanism during each cycle ofoperations thereof.

18. In a sewing machine, in combination, stitch-formlng mechanlsmincluding a nee-' dle loop-taker and bobbin, and thread-controllingmechanism'including a driven shaft, a crank-pin carried thereby andhaving two arms fixed thereto in an acute angular relaion, a strapconnected to one of said'arms, a stationary disk embraced by said strapand having a circular periphery in nonconcentric relation to the path ofthe crankpin, a take-up member, and a'link connected at its oppositeends to said take-up member and to the other arm on said crank-pin.

.14. In a sewing machine. stitch'forming mechanism includinga needle, aloop-taker and bobbin, and thread-controlling mechanism including adriven'shaft, a crank-pin carried thereby and having two arms fixedthereto in acute angular relation, a strap 7 connected to one of saidarms, an adjustable opposite ends to said takeup member and to I theother. arm on said crank-pin. p

i ,aoaaso 15. In a sewing machine having stitchitorming mechanism incombination threadcontrolling mechanism including a shaft, a pair ofelements confined to circular movement in relatively eccentric paths, apositive connection between said shaft and one of said elements, an armon one of said elements articulated with the other element, a second armarranged at an acute angle and fixedly connected to the first mentionedarm with which it forms a lever,a take-up member, and an articulatedconnection between said second arm and said take-up member fortransmitting the throw and arcuate movement of the second arm to thetake-up.

16. In a sewing machine, in combination, stitch-forming mechanism andthread-controlling mechanism including a shaft, 2. crank-pin thereon,arms on opposite ends of said crank-pin forming therewith a leverfulcrumed intermediate its ends, a stationary eccentric looselyembracing said shaft, a strap about said eccentric, one arm of the leverbeing articulated together, a take-up member confined to swing in aplane, a link connected to said take-up member and said other arm of thelever.

17. In a sewing machine, in combination, stitch-forming mechanismincluding a needle loop-taker and bobbin, threadcontrolling mechanismincluding a thread-engaging member, and means for moving said member.comprising articulated link lever and two eccentrically disposedcircularly movable elements acting upon the fulcrum and one end of saidlever to impart the compounded circular movement of the two elements tothe other end of the lever.

18. In a lock-stitch machine, an overhanging arm terminating in a head,a needle, a loop-taker, a bobbin, and thread-controlling mechanismincluding a thread-engaging member fulcrumed on the head, a shaft, adisk on the end thereof within the head, a bellcrank-lever fulcrumedintermediate its ends and eccentrically upon said disk with its armsarranged on opposite sides of said disk, a stationary disk disposedeccentrically of said driven shaft, a strap embracing said stationarydisk and articulated to an arm of said bellcrank-lever, anda link connecting the other arm of the bellcrank-lever and the thread-engagingmember.

19. In a sewing machine having stitchiiorming mechanism including aneedle and a shaft for operating the same, a thread-controllingmechanism including a thread-engaging member, a link connected at oneend to said member and having its other end confined to move in areentrantly curved path during each stitch-forming cycle of operations.

20. In a sewing machine, in combination,

stitch-forming and thread'controlling mechanism including athread-engaging member said strap and and an actuating element therefor,said actuating element comprising a pivotal crank provided with twoarms, the pivot and a point spaced therefrom on one of said armsconfined to move'in eccentrically disposed circular paths, and the otherarm having a connection with said thread-engaging member.

21. In a sewing machine, in combination with stitch-forming mechanism,thread-controlling mechanisni including a thread-engaging member, meanstor moving the thread-engaging member to govern the thread as demandedby the stitch-forming mechanism including a member connected to thethread-engaging member, and means for moving said second membercomprising a crank mounted on a pivot movable in a curved path, andmeans including an eccentric for turning the crank on the pivot as ittraverses said path.

In a sewing machine, in combination with stitch-forming mechanism,thread-controlling mechanism including a thread-engaging member, meanstor moving the thread-engaging member to govern the imparting to saidsecond member movement whereby a point on sald member spaced from saidconnection is given a rotary motion about a fixed axis and a motiontransverse with respect to said fixed axis to control the action of thethread, said latter means comprising a crank mounted on a pivot movablein a curved path, and means including an eccentric for turning the crankon the pivot as it traverses said path.

23. In a sewing machine, in combination with stitch-forming mechanism,thread-controlling mechanism includlng a pivoted thread-engaging member,means for moving the thread-engaging member to govern the thread asdemanded by the stitch-forming mechanism including a member having apivotal connection with said thread-engaging member, and means forimparting move ments to said second member comprising a crank mounted ona pivot movable in a curved path, and means including an eccentric forturning the crank on the pivot as it traverses said path.

24. In a sewing machine, in combination, stitch-forming mechanism, athread-control mechanism including a thread-engaging member, a linkconnected to the thread-engaging member, and means for moving said linkcomprising a crank mounted on a pivot movable in a curved path, andmeans including an eccentric for turning the crank on the pivot as ittraverses said path.

In testimony whereof, I have signed my name to this specification.

PARK A. HERB.

